1. Field of the Invention
The present invention relates to assemblies for the attachment of an operator compartment to the body of a vehicle, and more specifically to a new and improved assembly allowing for the simultaneous lateral and rotational movement of the operator compartment along the assembly.
2. Description of the Prior Art
Vehicles, particularly industrial vehicles, ordinarily have a seat, cab or compartment where the operator is positioned. Controls for the vehicle are located conveniently in front of the seat, or within the cab or compartment. For safety reasons cabs or compartments have been widely used in the art to prevent injury to the operator of the machine due to improper use, including rollover injury. While increasing safety, the inclusion of a cab or compartment can limit the motion and visibility of the operator of the machine. This can create inefficiencies as it increases the probability of error in the use of the vehicle. Since the cab or compartment must be reinforced to properly protect the operator, it is impossible to create perfect visibility from the cab. In many cases the cab is in a fixed position, and because of the dimension of the vehicle, critical lines of sight may be obstructed by portions or components of the vehicle itself.
It is known in the art to have vehicles and machinery where the cab or operator compartment turns or swivels relative to the vehicle chassis. While this movement changes the view of the operator, this view remains static with respect to the components of the machine involved. The static position of the operator can impair the operator's view with respect to the function of the vehicle.
The use of asphalt compactors are well known in the art. Asphalt compactors ride upon two large steel drums. The drums are located in the back and the front of the compactor. The drums are of a large circumference. The body of the compactor sits above and between the large steel drums. Because of the large circumference of the steel drums, the operator of the machine is relatively far from the ground. The size and the bulk of the machine can impair the operator's view of the asphalt which is to be compacted.
Traditionally such machines have a fixed seat, cab, or compartment for the operator. Depending on the machine, the seat or cab may be fixed near the center of the compactor, or it may be located toward one or the other of the sides of the compactor. If the cab is placed closer to one of the edges of the machine, it allows for the increased visibility of the asphalt and ground on that side of the machine upon which the seat is positioned. Unfortunately, the view of the other side of the machine is significantly impaired by such placement.
When compacting asphalt, it is of significant importance to ensure that all the asphalt is being compacted. This can be extremely difficult on a large compactor, where visibility is diminished. To overcome this problem compactors have been installed with an apparatus connecting the operator compartment to the compactor allowing for the lateral movement of the cab on the compactor. The lateral movement increases visibility by allowing the operator to get closer to ether side of the compactor to see the location of the compactor with respect to the already compacted asphalt. Even with the cab of the compactor fully extended to either side, it may not be possible for the operator to see the relationship of the edge of the steel drums of the compactor to the road surface which he or she is compacting.
An existing machine provides a large cab area in which the operator seat is attached to a ball bearing apparatus on a track. The seat is capable of movement back and forth along the track inside the large cab using a pin dropped into a hole to fix the seat position. Such a device may provide some improvement to the operator's field of view, but does not allow any lines of sight outside of the profile of the vehicle itself.
When paving large areas of asphalt, it is imperative that all the asphalt is compacted. To ensure this, the operator must run the edge of the steel drums of the compactor over the finished mat (compacted asphalt) to ensure that no portion of unfinished mat (un-compacted asphalt) remains. If the operator is unable to see the relationship of the finished mat to the steel drums of the compactor, then there is a greater chance that the operator will over-compensate, and run the compactor over a large portion of the finished mat; or worse, run off the asphalt onto the embankment thereby destabilizing the vehicle which could tip or roll over. Alternatively, the operator may under estimate the distance of the compactor to the unfinished mat, and leave a portion of unfinished mat between the strips of finished mat. At a minimum either situation creates inefficiencies as further runs over the asphalt will be required to fully compact the asphalt, not to mention the danger of a possible rollover.
Because compactors run at relatively slow speeds, if the operator misses a strip of pavement, the inefficiency is exaggerated as the operator must again slowly run the compactor along the length of the strip. If the contractor is constantly running over more of the finished mat than is needed, more runs of the compactor will be needed to accomplish the entire compacting of the asphalt surface, wasting time and resources.
With regard to other vehicles and off-highway machinery, it is also imperative to visually see the ground surface on any given side of the machinery. Usually machinery will have a fixed operator compartment, which severely restricts the operator's view. Therefore the operator must either rely on his or her own peripheral sense or enlist the help of co-workers outside of the machinery to properly perform the function involved. This results in increased labor costs for extra employee(s) needed to guide the operator of the machinery. There is also an increased risk of damage or injury to the off-highway machinery, the operator, and/or site workers from the impaired views.
It is therefore desirable to provide an apparatus for improving the lines of sight of an operator of a vehicle, including off-highway machinery and asphalt compactors, by providing an operator compartment or cab that is capable of wide-ranging movement relative to the vehicle itself.